The present invention relates to an improved method and apparatus for profiling grinding wheels.
When grinding profiled workpieces on grinders, e.g., round, flat, gear, and thread grinders, the object of conventional systems has been to profile the grinding wheel economically and accurately, and to render the grinding wheel capable of cutting again with the requisite trueness by dressing the wheel when it has become worn and dull.
To accomplish these objectives, there are various conventional methods currently used. One method includes moving along the contour of the grinding wheel with a single diamond or with a diamond-studded crushing roller by a template or a numerically-controlled dressing device, to thereby sharpen and profile the grinding wheel. This process is very flexible with respect to shaping, and therefore is suitable for limited production. However, the dressing periods are long, since the dressing tool makes only quasi point-by-point contact with the grinding wheel, and therefore must be guided along the contour by a relatively slow feed.
Another conventional method includes using a diamond-studded crushing roller that exhibits the whole outline and profiles the entire width of the grinding wheel simultaneously. This method results in shorter dressing periods, since the grinding wheel is engaged linearly by the crushing roller. However, practically it is suitable only for large-scale production, since the crushing roller is very expensive, a long lead-time is required for design and acquisition of the roller, and because it is impossible to subsequently change the shape.
A third conventional method includes crush dressing the outline with crusher rollers (steel rollers) at a low circumferential speed. However, this method has limited popularity today, and is applied exclusively to one-time production of special profiles.
A dressing method and device are described in U.S. Pat. No. 2,720,062, in which a grinding wheel is fed alternatively to a workpiece and to a dressing roller which trims it to the requisite shape. A conditioning roller having the same contour as the grinding wheel can be fed against the dressing roller to dress it. However, this method has all of the drawbacks of the aforementioned dressing methods, and therefore has not been put into practice.